The present invention generally relates to a method of physical chip identification to be used during communication between electronic apparatuses in the Ethernet.
2. Description of the Related Art
In general, information communication by using the internet may be the exchange of the properly-divided pieces of data (protocol data unit) shared among the information terminals (nodes) in the network. Those pieces of divided data may be attached with controlling information which is necessary to the management in the network. The configuration of those pieces of data and the controlling information may be called “format.” The format itself and the usage of the format may be regulated with one procedure called “protocol.” Any two information terminals that exchange information with each other may have to deal with data under the format that has a certain degree of consistency among those terminals.
The terms that are generally used to describe the protocol data unit may be “frame,” “packet,” “segment,” and so forth. These terms are separately used in different communication hierarchies.
The hierarchy structure (communication hierarchy) may be defined according to the design concept of the entire network system. The following structure may be a typical example. From the bottom layer up, there may be the physical layer (layer 1), the data link layer (layer 2), the network layer (layer 3), the transport layer (layer 4), and the upper layer (layer 5). However, this hierarchy is merely one of the examples. Under a different design concept, for example, the transport layer may be further divided into three layers, and, then, the number of the total layers may be seven, as is well-known. Anyway, the protocol data unit may be generally called “frame” in the data link layer (layer 2), “packet” in the network layer (layer 3), and “segment” in the transport layer (layer 4).
Those five layers may be described below.
To constitute a network as a physical form, the information apparatuses which serve as network nodes and the signal transmission pathways that connect the nodes to each other are indispensable. The signal transmission pathways may be either wired or wireless. Moreover, there may be several kinds of signals. For example, it may be roughly divided into an electrical signal and an optical signal. In other words, the nodes may be physically connected each other via wired/wireless signal transmission pathways, or via electrical/optical signal transmission pathways. Such a physical connection and transmission may be carried out in the physical layer (layer 1).
Even though the connection structure of the network is generally complex, both ends of a signal transmission pathway may have to be terminated by two nodes, respectively. The protocol data unit may be a mass of data to transmit through a plurality of signal transmission pathways. Accordingly, the two nodes that respectively terminate the two ends of one signal transmission pathway (e.g., a first node and a second node) may be subject to protocols which may be consistent with each other to some extent. If the protocols to which these nodes are subject are inconsistent, this signal transmission pathway may not be regarded as connecting the first and second nodes.
FIG. 1 illustrates a concept of a transmission method of a protocol data unit. Original data to be converted (coded) into protocol data unit may be input to a first node 2001 constituting a part of the network. The first node 2001 may be, for example, a computational terminal having a console, such as a keyboard, a mouse, a display and so forth. The first node 2001 may also be a tablet, a mobile phone, a smart phone, a terminal with a card reader, a seamier, a digital camera with net connection function, a sensor, and so forth. All of those information apparatuses may obtain some kind of information, convert it into a protocol data unit, and then send it to a signal transmission pathway 1000. By this way, a node which may have some kind of connection to the exterior of the network may be regarded as a peripheral node. In the case of FIG. 1, the first node 2001 may be an example of a peripheral node.
In a peripheral node (e.g., the first node 2001), the information inputted from the exterior of the network may be digitized. Subsequently, it may be converted into a protocol data unit according to a predetermined format. Alternatively, in the case that the information digitized in advance is input to a peripheral node, it may be converted into a protocol data unit according to a predetermined format. Anyway, the protocol data unit may be sent via the signal transmission pathway 1000 to another node whose format has a certain degree of consistency with the peripheral node (e.g., the first node 2001). In the example of FIG. 1, the second node 2002 may be the node to receive the signal.
The node in the opposite side of the signal transmission pathway 1000 (e.g., the second node 2002) may receive the above-mentioned protocol data unit and then converts it back into the digital data (i.e., decoding).
In the case that the above-mentioned first node 2001 is not a peripheral node, the first node 2001 may receive some kind of digital information from another node (e.g., a third node 2003) in the network. The digital data may be a protocol data unit coded by the third node 2003. The first node 2001 may decode this protocol data unit back to the original digital data according to a predetermined format. Hence, the predetermined format to which the first node 2001 is subject may have a certain degree of consistency with the format to which the third node 2003 is subject. However, in the case that this first node 2001 serves as a relay apparatus as described below, instead of decoding the protocol data unit, the first node 2001 may append the information related to the first node (e.g., the information indicating the protocol data unit that is transmitted via the first node) to the protocol data unit and then send the protocol data unit along with the appended information to the second node 2002 via the signal transmission pathway 1000. In this case, the format to which the second node is subject may have a certain degree of consistency with the format to which the third node 2003 is subject.
First of all, the information that is input from the exterior of the network or from the third node 2003 to the first node 2001 may be converted into a protocol data unit according to a predetermined format, which is then transmitted to the second node 2002 via the signal transmission pathway 1000. The second node 2002 may execute the inverse transformation (decode) of the received protocol data unit according to a predetermined format which may have a certain degree of consistency with the format to which the first node is subject. As a result, the original information before being input to the first node 2001 may be reproduced. This is a basic structure of the signal transmission of data. By doing so, a mass of data converted (coded) into the protocol data unit may be sent and received in the network.
In the above, the data transmission has been described in one direction from the first node 2001 to the second node 2002, and the usage of the protocol may be the same in the opposite direction of the transmission. For example, the first node 2001 and the second 2002 in FIG. 1 may swap their positions. In that event, first of all, the information that is input from the exterior of the network or from the third node 2003 to the second node 2002 may be converted into a protocol data unit according to a predetermined format, which is then transmitted to the first node 2001 via the signal transmission pathway 1000. The first node 2001 may execute the inverse transformation of the received protocol data unit, and then reproduce the original data before being input to the second node 2002.
FIG. 2 illustrates the relationship between the layer hierarchy and the data structure. The original data before transmission may be divided into pieces with proper sizes. Hereinafter, these pieces of divided data may be simply called “data.” At this moment, the layer in which data exists may be the upper layer (layer 5).
Next, a transmission control protocol header (TCP header) may be appended to this data. The TCP may be an abbreviation for Transmission Control Protocol and is a type of protocol. By doing so, the data with the TCP header may be called “segment.” The communication layer that deals with the segment may be the transport layer (layer 4).
In the case that the communication corresponding to FIG. 1 is in the transport layer (layer 4), the protocol data unit may be the segment, and, then, the transformation protocol may be TCP. If the first node 2001 receives the data, it may append a TCP header to the data according to the TCP format and then form a segment. This segment may be transmitted to the second node 2002 via the signal transmission pathway 1000. The second node 2002 may receive the segment and then decode it according to the TCP format to reproduce the original data. More specifically, the second node 2002 may remove the TCP header.
In the network layer (layer 3), an internet protocol header may be appended to the segment. In this case, the protocol data unit may be called “packet,” and the protocol may be IP. The IP protocol may be IPv4 and IPv6 according to the version.
In the case that the communication corresponding to FIG. 1 is in the network layer (layer 3), the protocol data unit may be a packet, and the transformation protocol may be IPv4, IPv6, and so forth. If the first node 2001 receives data (segment in this case), it may append an IP header to the segment according to the format of IPv4 or IPv6 and then form a packet. This packet may be transmitted to the second node 2002 via the signal transmission pathway 1000. The second node 2002 may receive this packet and then execute the inverse transformation (decoding) of the packet according to the format of IPv4 or IPv6 to reproduce the original segment. More specifically, it may remove the IP header. Alternatively, it may further remove the TCP header to reproduce the original data.
In the data link layer (layer 2), an Ethernet protocol header (Ethernet header) may be appended to a packet. In this case, the protocol data unit may be called “frame,” and the protocol may be the Ethernet.
In the case that the communication corresponding to FIG. 1 is in the data link layer (layer 2), the protocol data unit may be the frame. If the first node 2001 receives the data (packet in this case), it may append an Ethernet header to the packet according to the format of the Ethernet and then form a frame. In addition, a frame check sequence (FCS) may be appended in the format of the Ethernet, in order to check whether or not the packet may have been appropriately received. By doing so, the formed frame may be transmitted to the second node 2002 via the signal transmission pathway 1000. The second node 2002 may receive the frame and then execute the inverse transformation of the frame (decode) to reproduce the original packet. More specifically, the second node 2002 may check the FCS to confirm if the packet has been appropriately transmitted or not. The second node 2002 may also execute the procedure of restoration or retransmission as necessary. If it is confirmed that the packet has been appropriately transmitted, the second node 2002 may remove the Ethernet header and the FCS.
In the Ethernet standardization, the conversion in the lowest layer, i.e., the physical layer (layer 1), may be also defined. Namely, the conversion to an optical or electrical signal is defined. The converted frame may be passed to the line such as 10BASE-T.
The communication hierarchies (which are referred to “communication layers” or “layers” hereinafter) may be completely independent from each other, because they have a nested relation. More specifically, as shown in FIG. 2, the format of the segment (with only TCP header attached to data) in the layer 4 (transport layer) may include the format of the layer 5 (upper layer), i.e., only the data with no conversion. This may be because that the segment is not formed by irreversibly combining the TCP header with the original data but by simply attaching the TCP header to the original data. Similarly, the format of the packet (with only the IP header attached to the segment) in the layer 3 (network layer) may include the format of the layer 4 (transport layer), i.e., the segment. This may be because the packet is not formed by irreversibly combining the IP header with the segment but by simply attaching the IP header to the segment. Furthermore, the format of the frame (with only the Ethernet header and FCS attached to the packet) in the layer 2 (data link layer) may include the format of the layer 3 (network layer), i.e., the packet. This may be because the frame is not formed by irreversibly combining the Ethernet header, FCS, and packet together, but by attaching the Ethernet header and FCS to the packet.
In other words, no change happens in the upper communication layers even by replacing or changing the protocols or formats in the lower communication layers. For example, in FIG. 2, the TCP header and the original data (i.e., segment) may be unchangeable even by replacing IPv4 to IPv6 in the IP header of the layer 3 (network layer). In other words, the layer 4 (transport layer) may be free from any change in the layer 3 (network layer). The layer 5 (upper layer) may be also free from any change in the layer 3 (network layer) subsequent to the layer 4.
In a similar way, the original data may be unchangeable even by replacing the TCP header to another one. That is, the layer 5 (upper layer) may be free from any change in the layer 4 (transport layer). Furthermore, the packet may also be unchanged even by replacing the Ethernet header with another one. For example, the packet may be unchangeable even by changing the protocol from the Ethernet to point-to-point (PPP). Accordingly, the layer 3 (network layer) may be free from any change in the layer 2 (data link layer). The layer 4 (transport layer) may be also unchangeable subsequently to the layer 3 (network layer). The layer 5 (upper layer) may be unchangeable subsequently to the layer 4 (transport layer).
Furthermore, something may be changed in the layer 1 (physical layer). For example, the signal transmission pathway may be changed from optical fibers to wireless LAN. Even in this case, the contents of the information (e.g., frame) which are transmitted via wireless LAN may be the same as the contents of the information (frame) which is transmitted via optical fibers. In other words, the layer 2 (data link layer) may be free from any change in the layer 1 (physical layer).
The layer 3 (network layer) may be also unchangeable subsequently to the layer 2 (data line layer). No change happens in the layer 4 (transport layer) subsequently to the layer 3 (network layer). No change happens in the layer 5 (upper layer) subsequently to the layer 4 (transport layer).
By this way, it may be found that no change happens in any upper communication layers even by changing something in any lower communication layer. This is a design that will not hinder the development of future technological innovations.
On the other hand, the present invention may be related to the physical layer and the data link layer in the bottom layers. Base on the reason like this, the present invention may not affect on any data to be transmitted.
The protocols adopted in the same layer may have to be consistent with each other. However, they may not be necessary to be consistent with each other as long as they belong to different layers. In other words, to design layers is to design the relationship among a plurality of protocols. In the above, the physical layer and the data link layer (layer 1 and layer 2) are different from each other. However, in another concept of layers, they may be regarded as one layer by making them subject to a common Ethernet protocol. In this case, the number of the layers may decrease as 4 by 1. Moreover, the formats of the transport layer (layer 4) and the network layer (layer 3) may be also combined and then called “TCP/IP format.” Alternatively, there may be an opposite concept to divide the layers. For example, in an OSI reference model, the upper layers may be further divided into three, which may be a session layer (layer 5), a presentation layer (layer 6), and an application layer (layer 7) from the bottom up.
In the case that the information is input from the exterior of the network to the first node 2001 as shown in FIG. 1, the original data has been divided into pieces having a predetermined length. The data may be formatted according to the TCP/IP format and then converted to packets. A packet may be converted into a frame according to the Ethernet format. In the physical layer (layer 1), this frame may be sent and received as a wired, wireless, optical or electronical signal via the signal transmission pathway 1000 having physical substance. Hence, the first node 2001 and the second node 2002 may be information apparatuses having physical substances.
Next, in the case that a packet is input from the third node 2003 in the network layer (layer 3) to the first node 2001, this packet may be converted into a frame according the Ethernet format and then sent to the second node 2002 via the signal transmission pathway 1000. Hence, all of the first node 2001, the second node 2002, and the signal transmission pathway 1000 may have physical substances.
Subsequently, in the case that a segment is input from the third node 2003 in the transport layer (layer 4) to the first node 2001, this segment may be converted into a packet according to the IP format and then sent to the second node via the signal transmission pathway 1000.
Hence, all of the first node 2001, the second node 2002, and the third node 2003 may be logical substances and not related to any physical substance. For example, those may be virtual nodes allocated to operating systems. Thus, the signal transmission pathway 1000 may be also a virtual transmission pathway and not beyond and may have no relation to any physical substance.
In other words, in the network of the TCP/IP format (network layer), both nodes and signal transmission pathways may be logically defined, and then may be virtual substances and are not related to any physical substance. On the contrary, in the network of the Ethernet format (data link layer), both nodes and signal transmission pathways may have physical substances. For example, the answer to the question: “which terminal this node corresponds to?” or “which LAN cable the signal transmission pathway corresponds to” may be actually found.
In FIG. 3, there may be a fourth node 2004 between the first node 2001 and the second node 2002. Some kind of data may be input from the exterior of the network or from the third node 2003 to the first node 2001. The first node 2001 may connect to the fourth node 2004 via the first signal transmission pathway 1001. The fourth node 2004 may connect to the second node 2002 via a second signal transmission pathway 1002.
The connection of the first node 2001 and the fourth node 2004 via the first signal transmission pathway 1001 may be almost similar to that of the first node 2001 and the second node 2002 via the signal transmission pathway 1000 as illustrated in FIG. 1. However, the fourth node 2004 may work partially different. In other words, in the case that the fourth node 2004 may serve as a relay between any two nodes (e.g., a relay between the first node 2001 and the second node 2002), as shown in FIG. 3, the fourth node 2004 may be able to transfer a protocol data unit, which is input from the first node 2001 via the first signal transmission pathway 1001, to the second node 2002 via the second signal transmission pathway 1002 with no decode. Alternatively, the fourth node 2004 may transfer the protocol data unit with some kind of editing.
By this way, the data that is input to the first node 2001 from the exterior of the network or the third node 2003 may be converted into a protocol data unit according to a predetermined format in the first node 2001. The protocol data unit may be then transmitted to the fourth node 2004 via the first signal transmission pathway 1001. The fourth node 2004 may not execute the inverse transformation (decoding) and then transmits the protocol data unit to the second node 2002 via the second signal transmission pathway 1002.
Alternatively, a part of the received protocol data unit (such as the header) may be edited and then transmitted to the second node 2002 via the second signal transmission pathway 1002. The second node 2002 may execute the inverse transformation of the received protocol data unit according to a predetermined format, and then reproduce the data before being input to the first node 2001. Hence, the predetermined format conformed by the second node 2002 may have a certain degree of consistency with that conformed by the first node 2001.
More specifically, in the case that the fourth node 2004 edits and then transmits a received protocol data unit to the second node 2002 via the second signal transmission pathway 1002, the header associated to the layer under consideration may be edited and then transmitted.
For example, in the case that the fourth node 2004 belongs to the data link layer (layer 2), a frame may be transmitted after editing the Ethernet header. More specifically, at least the identification of the fourth node 2004 serving as a relay may be attached to the frame. Those relay locations may be regarded as the addresses having physical substances (physical addresses). Those physical addresses may be called, particularly, MAC address. The MAC addresses may be inherent to Ethernet apparatuses (e.g., Ethernet cards).
Alternatively, in the case that the fourth node 2004 belongs to the network layer (layer 3), a packet may be transmitted after editing the TCP/IP header. For example, at least the identification corresponding to the system of the fourth node 2004 serving as the relay may be attached to the packet. Anyway, this may enable tracing via the nodes this protocol data unit has been transmitted when the second node 2002 receives it. Those relay locations may be regarded as the addresses having no physical substances (logical address). This logical address may be called, particularly, IP addresses. The IP addresses may be, for example, inherent to the operating systems.
It may be self-evident that the physical address and the logical address differ from each other. For example, an electronic apparatus constituting the fourth node may be replaced. In this case, the operating system of the electronic apparatus constituting the fourth node before the replacement (old electronic apparatus) may have to be re-installed to the electronic apparatus constituting the fourth node after the replacement (new electronic apparatus). Thus, the physical address which is an intrinsic identification of the electronic apparatus having the physical substance may be changed. On the other hand, the IP address intrinsic to the operating system may be handed over by the fourth node after the replacement. This may be one of reasons that the logical network (TCP/IP network) is extensively adopted.
In the example of FIG. 1 and FIG. 3, the first node 2001 and the second node 2002 may be exchanged. In other words, the data that is input from the exterior of the network or from the third node 2003 to the second node 2002 may be converted into a protocol data unit according to a predetermined format, which is then transmitted to the fourth node 2004 via the second signal transmission pathway 1002. The fourth node 2004 may transfer the received protocol data unit to the first node 2001 with no inverse transformation (decoding) via the first signal transmission pathway 1001.
Alternatively, the fourth node 2004 may edit the received protocol data unit according to a predetermined format and then transmit it to the first node 2001. The first node 2001 may execute the inverse transformation of the received protocol data unit (decoding) according to the predetermined format, and then reproduce the original data before being input to the second node 2002. Hence, the predetermined format that the first node 2001 conforms may have a certain degree of consistency with that the second node 2002 conforms. The figures to illustrate it may be self-evident from FIG. 3 and thus omitted. Hence, the edition with the predetermined method may imply, for example, that the physical address or the logical address of the fourth node is attached to the protocol data unit.
There may be more than one signal transmission pathway connecting to the nodes in the network. In other words, as shown in FIG. 3, the fourth node 2004 may connect to two signal transmission pathways (the first signal transmission pathway 1001 and the second signal transmission pathway 1002). FIG. 4 illustrates another example. In other words, the first node 2001 may connect to one end of the four signal transmission pathways (the first signal transmission pathway 1001, the second transmission pathway 1002, the third signal transmission pathway 1003, and the fourth signal transmission pathway 1004). The other ends of those signal transmission pathways may connect to the second node 2002, the third node 2003, the fourth node 2004 and the fifth node 2005, respectively.
Furthermore, the fourth node 2004 may connect to the sixth node 2006 via the fifth signal transmission pathway 1005. Of course, FIG. 4 illustrates a part or one of the examples of the complex network structures. In general, a large scale and a complex network structure may be constructed by connecting a plurality of nodes to a plurality of other nodes.
However, referring to FIG. 5, no matter how large and complex the network structure is, the element of the network may be one signal transmission pathway, with the ends of which terminated by two nodes. This may definitely imply that the elements of the network include at least two nodes and one signal transmission pathways. The above mentioned protocols may be defined per element. Accordingly, an aggregation of elements provided with the same or similar protocols which are consistent with each other may belong to a same communication layer. A plurality of elements belonging to a same communication layer may be able to form a local area network (LAN). The first proposed LAN is a network by the Ethernet and bunches the data link layer (layer 2). From such a historical background, LAN and Ethernet may be regarded almost as synonymous words.
The information apparatuses connecting to the LAN as nodes may be respectively allocated with the intrinsic management numbers (MAC address) according to the Ethernet protocol. Hence, MAC is an abbreviation of the media access controller. In other words, a frame may be formed by attaching the MAC addresses of the sender and receiver and the FCS to a packet as an Ethernet header or a part of its header. In other words, a network formed by the information apparatuses (having physical substance) that are connected to each other based on the MAC addresses may be a network in the data link layer, that is, LAN.
Referring to FIG. 5, the first node 2001 and the second node 2002 may be the information apparatuses that are connected to each other via Ethernet. Hence, the protocol data unit may be a frame. In the case that a frame is transmitted between those two information apparatuses, both the information apparatuses of the receiver (e.g., the second node 2002) and the sender (e.g., the first node 2001) may be subject to the Ethernet protocol. In other words, the management number of the first node 2001 may be the MAC address of the sender, and the management number of the second node 2002 may be the MAC address of the receiver. FIG. 5 illustrates an element of a network and is a part of a much more complex network. For example, the first node 2001 may connect to 2nd-5th nodes (2002, 2003, 2004, 2005), as shown in FIG. 4.
Hence, it may be assumed that all nodes are subject to a same protocol. For example, the first node may send the above-mentioned frame via the first to fourth signal transmission pathways (1001, 1002, 1003 and 1004). It may be assumed that the MAC address of the receiver, which is included in the Ethernet header of the frame to be transmitted, is the MAC address of the second node 2002 for example. The third node 2003 may check the MAC address of the receiver of this frame and does not receive it. The fourth and fifth nodes (2004 and 2005) may not receive it, either. Only the second node 2002 may receive it. Furthermore, the second node 2002 may know that this frame was sent from the first node 2001 by checking the MAC address of the sender.
The case may assume that the first node 2001 codes a frame and sends it to the second node 2002, and that the second node 2002 receives the frame and decodes it to reproduce the original packet. Referring to FIG. 1 as an example, the packet may be input from the exterior of the network or from the third node 2003 to the first node 2001. The first node 2001 may attach the MAC address of the first node as the sender and the MAC address of the second node as the receiver to this packet. Furthermore, FCS may be attacked to form the frame. The frame formed this way may be transmitted to the second node 2002 via the first signal transmission pathway 1000.
If the frame arrives at an information apparatus of the receiver (the second node 2002) according to the MAC address, the receiver may decode the frame according to the Ethernet protocol and then reproduce the digital information before being input to the data link layer (packet). Hence, the receiver may be permitted to request the repairing or the retransmission as necessary according to the FCS. In the case of no retransmission, the transmission of the packet in the data link layer may be completed as a result. To decode in the data link layer may be to remove the excess codes attached to the original digital data (packet) such as MAC addresses and FCS according to the Ethernet protocol. The receiver (the second node 2002) may be able to check the controlling information of the sender with the received frame and then decide whether to decode or transmit it.
The reproduced digital information may be a piece of data in the TCP/IP format, that is, a packet. It may be called an IP packet which may be equivalent to the digital data before being coded by the first node 2001 as the sender. As mentioned above, the packet may be a unit of communication data in the network layer (layer 3). The protocol in the network layer may be IP protocol (i.e., IPv4 or IPv6).
In the case that an element of the data link layer (layer 2) may be formed by FIG. 1 and FIG. 5, the Ethernet header may be like an envelope. The MAC address of the receiver may be like an address of the destination written in the envelope. The MAC address of the sender may be like an address of the sender written in the envelope. The FCS may be like a contents-certification. Hence, the contents of the envelope may be a packet. Accordingly, to code a packet with the Ethernet may be to enclose the packet in the envelope in which the addresses of the sender and receiver are written. To decode a frame may be to open the envelope. The contents in the envelope and the items written in the envelope may be independent from each other. This may correspond to the independency of layers, which is mentioned above. For example, the contents of the envelope may be unchangeable, even though the house number or the name of the town is changed due to land readjustment.
In the case that FIG. 1 and FIG. 5 may form an element of an upper layer by one (network layer), the envelope may be an IP header. The IP header may contain an IP address of the addresses of the sender and receiver in the network layer. The contents of the envelope may be a segment. To attach the IP header may be to enclose the segment. On the other hand, to remove the IP header may be to open the envelope. Actually, those IP addresses may be allocated with a certain relation to an upper layer by one (transport layer). In this case, the contents of the envelope may be a piece of divided data.
The MAC address may be called a physical address, since each MAC address may be allocated to an actual information apparatus (the node of physical substance). Any piece of the digital data linked to some kind of physical substance may be therefore allocated with the MAC address. In contrast, IP addresses may not always be related to the physical substances. In other words, the IP address may be allocated to a node which the operating system logically defines, and then called the logical address. By this way, the MAC address as well as the IP address may be attached to a piece of the digital data (protocol data unit) which goes through at least one information apparatus with physical substance while transmitting on the internet.
Thus, the MAC address which is a management number of the information apparatus may be used as a backstage pass, in contrast to the IP address which is an address on the internet (e.g., destination of packet). In other words, information may be sent to the interior of a lump of the networks on the internet (e.g., LAN). Apparatuses inside this network, or stem nodes or routers which may manage the network may receive the frames from only the information apparatuses that have been registered in advance. The MAC address of the sender may be confirmed to distinguish whether or not the corresponding frame actually comes from the apparatuses registered in advance. Only by confirming that the sender is registered in advance can the envelope arriving at the receivers be opened (i.e., the frame is decoded) to receive the packet. Otherwise, the envelope may not be opened (i.e., the frame is not decoded).
MAC address may be allocated to an Ethernet card equipped in the information apparatus as an intrinsic management number. It is standardized by the Institute of Electrical and Electronics Engineers (IEEE) with the length being 48 bits (6 bytes). Accordingly, it may be formed of sequences whose information volume is more than 280 trillion. One bit among them may be allocated to a so-called UL bit. In the case that the MAC address is a global address, UL bit is 1 and, otherwise, is 0. In other words, in the case of the global address (UL bit=1), MAC addresses may have to be allocated with no duplication all over the world. It should be noted that the MAC addresses may have to be allocated with no duplication to not only the information apparatuses that are being used on active service but also those having been disposed or lost. It may be because the MAC addresses may be respectively allocated to the information apparatus with physical substance.
Another bit among the 48 bits may be allocated to a so-called IG bit. In the case that the IG bit is 0, it may indicate a unicast communication and otherwise a multicast communication. The unicast communication may be a frame is sent to a unique destination in the network of a plurality of information apparatuses. In contrast, the multicast communication may be a frame is sent to a plurality of destinations in the network. By this way, 46 bits after removing those two bits of UL bit and IG bit from 48 bits may be the actual freedom of the MAC addresses to be allocated. It may be about 70 trillion in amount. The 48 bits including those two bits of UL bit and IG bit may be divided by six 8-bits, and then each 8 bits (one byte) may be represented by a hexadecimal.
In FIG. 6, a typical example of an Ethernet card may be illustrated. An Ethernet card 3000 may include mainly a nonvolatile memory 3010 storing a MAC address and a chip of operational processing unit fora media access controller (MAC) 3020. The Ethernet cards may be, in general, implemented into information apparatuses to be connected to each other via LAN and so forth.
Due to this, it may be called a LAN board or LAN card. However, the standardization of the LAN card or LAN board almost conforms with the Ethernet format, and the Ethernet card and the LAN card are synonymous. FIG. 6 illustrates an example where an Ethernet card is equipped in a printer, a router, a desktop personal computer, and so on. There may be an Ethernet connector at the backside of the Ethernet card. Thus, the connector may be exposed at the backside of the information apparatuses equipped with the Ethernet card. A LAN cable may be inserted into this Ethernet connector. Alternatively, an antenna may be attached to the Ethernet card, and the corresponding information apparatus may be connected by wireless LAN. A basic structure may be similar to this example in the case that the Ethernet card is connected to different information apparatuses.
In the case when the information apparatus boots or when the information apparatus is connected to the network in a wired/wireless manner, the operating system of the information apparatus may read the MAC address from a nonvolatile memory 3010 equipped on the Ethernet card. A main processing unit of the information apparatus may write this MAC address to a chip of the processing unit for the media access controller (MAC), which is equipped in the Ethernet card. When data is sent from the information apparatus (sender) to another information apparatus (receiver) connected to the network, the MAC address written into the chip of the processing unit for the media access controller (MAC) may be attached to the frame as a MAC address of the sender. By this way, the operating system may allocate the MAC address to the information apparatus with a physical substance (actually, the Ethernet card). In this manner, the MAC address may not be defined regardless of the physical substance.
It may thus be found that the Ethernet card is an example of network cards to be used for connecting information apparatus to the network. In other words, an information apparatus may require at least one Ethernet card, and at least one MAC address may be allocated to the Ethernet card. The number of the MAC addresses of the information apparatuses that have been used (spent MAC addresses) as well as being used on active service may be increased, as the number of the information apparatuses connecting to the internet is increasing.
On the other hand, the progress of the information and communication industry has been rapid since the beginning of the 21th century. More recently, the vast market is being made. It may be expected that everything, such as home electric appliances, houses, cars besides information terminals, is connected to the network. It may be called Internet of Things (IoT) or Internet of everything (IoE), which may not belong to any existing market and may even change the social structure.
It may be regarded that, in such a super great Internet of Things, the number of information apparatuses connecting to the network may be from several trillion to several ten trillion. Then, an era of trillion nodes may be coming soon. It may be expected in the concept of trillion nodes that the sensors connecting to the network are spread all over the world for collecting unpreceedingly detailed and great quantity of data. Thus, plenty of social problems may be solved by analyzing the collected data with the advanced computing technology. This conceptual plan has been spread from an international conference called TSensors Summit held in 2013.
What may happen if the present Ethernet system is expanded to the Internet of Things with no revision? The MAC addresses may be allocated to the whole personal belongings as well as the conventional information apparatuses. Then, it may be spread all over the world. In other words, several trillion of MAC addresses may have to be allocated simultaneously with no duplication all over the world in the global mode (UL bit=1). However, this figure, i.e., several trillion, may be the number of the information apparatuses connecting to the network on active service. The number of the spent MAC addresses may become 10 trillion or more by the time the Internet of Things becomes popular, if all information apparatuses having been used in the past as well as out of use due to some kind of reason are considered. As mentioned above, the limit of the number of MAC addresses may be actually about 70 trillion. It may be just a matter of time that the MAC addresses are used up.
One of the solutions to avoid the depletion of MAC address may be the revision of the MAC address. For example, the MAC address may be deleted when the corresponding information apparatus is disposed, and those not connected to the network for more than five years may be regarded as being disposed. Then, those MAC addresses may be reallocated to other information apparatuses. Indeed, the MAC addresses may be editable as necessary, as long as they are stored in nonvolatile memory chips. For example, in the operating system such as Widows Windows VISTA, the MAC address may be revised by the device manager. Also, there is also an application tool in the network to revise the MAC address.
However, such a revision of the MAC address may have to be executed with no duplication all over the world in the global mode (UL bit=1). However, it is concerned that the duplication of the MAC addresses will cause a malfunction of the network or make the network security vulnerable.
The nodes of the Internet of Things may include sensors to be used in trillion nodes as well as information apparatuses which the personal end users use to connect to the network. If the world population is seven billion, about 150 MAC addresses may surround a personal end user in average under the assumption that there are one trillion nodes all over the world. Among them, there may be less than 10 MAC addresses allocated to the information apparatuses by which a personal end user uses to connect to the network. The residual 140 MAC addresses may be out of management. Of course, the number of the nodes may be more than one trillion in the era of trillion nodes. In the developed countries, the average number of MAC addresses surrounding a person may be much more than 150.
Some of those nodes may involve a system to control the apparatuses surrounding a person as well as personal information. Even while a trained expert tries to control all the nodes spread over the world, it may be extremely hard to simultaneously control more than several trillion nodes. If it was capable, it would be a difficult problem of who would control the central management system responsibly. It may not be preferable that one private company executes the central control selfishly. It may not be realistic at the present that the artificial intelligence having more ability than human beings execute the central control.
Which kind of problem may occur if no one is able to control the all the nodes? For example, it may be possible for a malevolent hacker to hijack a node out of appropriate management and to abuse the node as another person. If such a spoofing is rampant, it may be a big social problem. An expensive information apparatus may be protected by advanced security technology. However, as briefly explained above, the number of the information apparatuses under the control with the advanced security technology may be at most 10 per person in average. In contrast, the advanced security technology cannot be used to protect widespreasd sensors that are manufactured at a lower cost as possible. As mentioned above, the number of these sensors may be 140 per person in average, if the number of nodes reaches one trillion. In other words, a network user in the near future may be surrounded by at least 140 incognita sensors while using 10 secure information apparatuses.
Briefly speaking, the sensors to be connected to the Internet of Things may be hacking devices themselves. Those may be used for social wellness in good faith, whereas the essence may be an endeavor to solve a social problem by using hacking technologies. It may be an opposite side of the same coin as malevolent hackers' attack.
Even though there is no malevolent hacker, the duplicate usage of the MAC address may cause a malfunction of the network. For example, two different sensors may collect different information and then send it to a server simultaneously. If those two different sensors accidentally have the same MAC address, the server may misunderstand that the two inconsistent information come from one sensor. For example, an object inspected by a first sensor is red, and another object inspected by a second sensor is blue. If the first and second sensors' MAC addresses are overlapped, the information that this server receives may be that the color of the inspected object is simultaneously blue and red. If this is used for an auto-driving system, what may happen? A traffic light on a certain cross-point may be simultaneously red and blue.
It may be impossible for a logical address to fix such a problem. It may be because that the logical address is not related to any physical substance. In other words, as long as the Internet of Things is a network among nodes with physical substances, only the cumulative experience and effort of operating the network under the TCP/IP format cannot appropriately manage the Internet of Things. By this way, it may be revealed that the problem to be solved for the industrial application of the Internet of Things (e.g., industry 4.0 and industrial internet) is essentially different from the expansion of the conventional information technology.
For example, there may be plenty of manufacturing apparatuses in a production line in a factory. Those manufacturing apparatuses may cooperate with each other and manufacture products. It may be indispensable to optimize the cooperation of the manufacturing apparatuses as well as to tune the setting of each manufacturing apparatus for improving the product yield. To improve such an optimization, all the manufacturing apparatuses may be managed by a computer. For this purpose, all apparatuses may have to be connected to the factory network. There may be small and large apparatuses. Large apparatuses may be divided into a plurality of parts, and each part may be connected to the factory network. The factory network may be enlarged as the factory is advanced and enlarged. In the conventional information technology, the computer program may execute the processes. In contrast, the cooperation control may be managed by the computer program, whereas the manufacturing processes may be executed by the equipment and apparatuses with physical substances.
Currently, the information terminals with such physical substances may be allocated with MAC addresses. The above-mentioned duplication of MAC addresses may cause a malfunction of the manufacturing line. Optionally, a malevolent hacker may be capable of forcing the factory itself to stop the function by hacking. The breakdown of the factory of the main industry may be a national security issue. The damage cost may be equivalent to a large scale national disaster or direct attack by missiles.
On the other hand, the conventional security of the information communication on the internet may, for example, mainly aim at protecting the data transmitting through the signal transmission pathway 1000 in FIG. 5 and suppresses hacking a stem node by a combination of accounts and passcodes. Anyway, it may be regarded as encryption technology. It may be impossible for the encryption technology to matter which kind of physical substance is connected to the ends of the signal transmission pathway 1000 shown in FIG. 5. It may be because the conventional internet is actually a logical network. However, in the Internet of Things, the sender and receiver of the data may have to be identified as physical substances. Therefore, the physical identification may be necessary to identify the physical substances connecting to the ends of the signal transmission pathway.
Briefly speaking, the MAC address may be an editable digital identification of an Ethernet card with a physical substance. Then, there may be a method to regard the MAC address as digital identification for the Internet of Things. However, it may be a problem as previously shown that the MAC address is editable and will be used up soon. As shown in FIG. 6, the MAC address is essentially a code of 48 bits stored in a nonvolatile memory.